Mouthpiece block for underwater breathing apparatus



FIG. 1 is a perspective view of a mouthpiece block for underwater breathing apparatus showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is an elevation as seen from the right of FIG. 2;

FIG. 4 is an end elevation thereof;

FIG. 5 is a cross section taken on line 5--5 of FIG. 3;

FIG. 6 is a cross section taken on line 6--6 of FIG. 3; and,

FIG. 7 is a cross section taken on line 7--7 of FIG. 5.

The broken lines are shown for illustrative purposes only. 

The ornamental design for a mouthpiece block for underwater breathing apparatus, as shown and described. 